The Apple iPhone 5s was announced on September 10, 2013. Repair of this device is similar to the previous models, and requires screwdrivers and prying tools. Available as GSM or CDMA / 16, 32, or 64 GB / Silver, Gold, and Space Gray.

Issue with lines showing up and touchscreen not working.

So just recently my iPhone started to have lines slowly pop up on it after unlocking it. What tends to happen is I can unlock the phone, use it for a little while then the lines will pop up and the touchscreen will stop working from there.

The only thing I have found that is correlates to is when I turn down the brightness it makes less lines less quickly, to where if I use full brightness it just will fill with lines almost instantly.

Also when I blow into the SIM slot, the lines will disappear from the screen for a little bit before coming back again in a few min.

I have factory reset my phone, restarted my phone and tried many different things but have not been able to figure out why. I have also just let my phone out for 48 hours off and still have the problem.

I don't think its water damage but it may be for I have not drooped my phone in any liquids or anything recently, but I don't know for sure.

It sounds a bit like the Touch Disease that afflicts the iPhone 6+. You can go to my profile and follow the link to my blog where I explain this in more detail or do a Google search. It's not a typical problem on the 5S but it can happen as well. Whatever it is, it seems to be related to heat. When your device is warm the problem occurs. Blowing on the SIM slot probably has a cooling effect.

If you want to try and fix this yourself, the first thing I would try is to replace the screen assembly. You could buy or use a known-good screen from another device. If the problem persists, you could try to run the phone without cameras or sensors to see if it is related to peripherals.

Otherwise, it could be a logic board problem. If your lucky, it could be poorly connected flexes but in a worst case, it could be with the electronics. That would require a micro-soldering repair.